&#34;multi-effect&#34; forming tooling for high-temperature forming

ABSTRACT

A forming tooling including a fixed part and a moving part set in action by a one-way press, in a first direction, the tooling varying between an open position and a closed position in which the moving part applies pressure to the fixed part; the moving part including moving dies capable of starting to deform the metal workpiece through a translational movement of the dies in a second direction simultaneous with the translational movement of the dies in the first direction during closure of the tooling, the moving dies being capable of moving away from the metal workpiece through a reverse translational movement of the moving dies, in the second direction, simultaneously with the translational movement of the moving dies in the first direction during opening of the tooling.

The present invention relates to a “multi-effect” forming tooling forhigh-temperature forming of metal workpieces such as for example a metalreinforcement for a composite or metal turbine engine blade.

The “multi-effect” forming tooling according to the invention isparticularly suitable for shaping workpieces with a complex geometricalshape such as a metal reinforcement for the leading edge of a turbineengine blade.

The field of the invention is particularly that of turbine engines andmore specifically that of turbine engine fan blades, in composite ormetallic material, wherein the leading edge comprises a metal structuralreinforcement.

However, the invention is also applicable to the production of anyworkpieces with a complex geometrical shape and to the production ofmetal reinforcements intended to reinforce a leading edge or a trailingedge of a blade from any type of turbine engine, whether terrestrial oraeronautical, particularly a helicopter turboshaft or a jet turbineengine.

It is noted that the leading edge corresponds to the anterior part of anaerodynamic profile that faces the flow of air and divides the air flowinto a lower surface air flow and an upper surface air flow. Thetrailing edge corresponds to the posterior part of an aerodynamicprofile where the lower surface and upper surface flows meet.

Turbine engine blades, particularly fan blades, undergo significantmechanical stresses, particularly connected to the rotation speed, andmust satisfy strict weight and volume conditions. One of the optionscontemplated for reducing the blade weight is the use of compositematerials for their manufacture.

Equipping fan blades of a turbine engine, made in composite materials,with a metal structural reinforcement extending over the entire heightof the blade and beyond their leading edge as mentioned in documentEP1908919 filed by SNECMA is known. Such a reinforcement enables thecomposite blading to be protected during an impact by a foreign body onthe fan, such as, for example, a bird, hail or else stones.

In particular, the metal structural reinforcement protects the leadingedge of the composite blade by preventing delamination and fiberbreakage risks or else damage by fiber/matrix debonding.

Conventionally, a turbine engine blade comprises an aerodynamic surfaceextending, in a first direction, between a leading edge and a trailingedge and, in a second direction substantially perpendicular to the firstdirection, between a foot and a top of the blade. The metal structuralreinforcement follows the form of the leading edge of the aerodynamicsurface of the blade and extends in the first direction beyond theleading edge of the aerodynamic surface of the blade to follow theprofile of the lower surface and the upper surface of the blade and inthe second direction between the foot and the top of the blade.

In a known manner, the metal structural reinforcement is a metalworkpiece in titanium made entirely by milling from a block of material.

However, the metal reinforcement for the leading edge of the blade is acomplex piece to make, necessitating many refinishing operations andcomplex equipment involving significant production costs.

In this context, the invention aims to resolve the problems mentionedabove, by proposing a “multi-effect” forming tooling capable of formingmetal workpieces at high temperature, such as a metal reinforcement ofthe leading edge or trailing edge of a turbine engine blade enablingsimplification of the manufacturing process and a significant reductionin the costs of producing such a workpiece by proposing a “multi-effect”tooling implemented by a single action press.

For this purpose, the invention proposes a “multi-form” forming toolingcapable of high temperature forming of metal workpieces, said toolingcomprising a fixed part and a moving part set in action by a one-waypress, in a first direction, said tooling varying between an openposition and a closed position in which the moving part applies pressureto said fixed part; Said tooling being characterized in that said movingpart comprises moving means capable of initiating deformation of saidmetal workpiece through a translational movement of said means in asecond direction Y simultaneous with the translational movement of saidmeans in said first direction during said closure of said tooling, saidmoving means being capable of moving away from said metal workpiecethrough a reverse translational movement of said moving means, in saidsecond direction, simultaneously with the translational movement of saidmoving means, in said first direction, during said opening of saidtooling.

One-way press is understood to refer to a single action press onlycomprising one working axis, generally the vertical axis with relationto the bearing plane of the press, as opposed to double or else tripleaction presses, respectively comprising two or three working axesoriented in different directions.

“Multi-effect” is understood to refer to deformation in severaldirections intervening in several places on the workpiece simultaneouslyin opposition to single action deformation resulting from a singlestress applied locally in a single direction.

Thanks to the invention, it is possible to carry out multi-effectdeformation (i.e., simultaneously in different directions) by means ofan inexpensive single action press, under high temperature conditions,i.e., the temperatures necessary for forging the workpieces to beproduced.

In the advantageous case of producing a metal reinforcement for aturbine engine blade, the workpiece is deformed and twisted in severaldirections in a single operation with a single action press at atemperature greater than 850° C. (on the order of 940° C. for theproduction of a titanium reinforcement). Therefore, the toolingaccording to the invention obviates the need for a complex production ofreinforcements by a method of milling in the mass from flats requiringlarge volumes of material and, consequently, the tooling enables thequantities of raw materials necessary for producing such a metalreinforcement to be reduced.

The metal reinforcement with a complex shape is made in a simple andquick manner from a preform obtained from a simple metal bar and asuccession of forging steps such as described, in particular, in patentapplication SNECMA FR1055066. The preform is then shaped in athree-dimensional manner at high temperature in the “multi-effect”tooling by means of a single action press.

Therefore, the tooling according to the invention enables multi-effectdeformation (i.e., simultaneously in different directions) to be carriedout by means of an inexpensive single action press, under hightemperature conditions, i.e., beyond 850° C.

The “multi-effect” tooling according to the invention may also presentone or more of the characteristics below, considered individually oraccording to all technically possible combinations:

-   -   said tooling is an isothermal tooling capable of forging at a        temperature greater than 850° C.;    -   said fixed part comprises a die presenting two inclined walls        capable of displacing said moving means in said second direction        Y during said closure of said tooling;    -   each of said moving means comprises an inclined face parallel to        one of said inclined walls of said die of the fixed part;    -   said moving part comprises at least one spacer integral with the        movements of said is moving part capable of moving away from        said workpiece in said second direction Y during said opening of        said tooling;    -   said fixed part comprises means capable of forming a reference        enabling said metal workpiece to be positioned in said tooling;    -   said tooling is capable of forming a metal reinforcement for the        leading edge or trailing edge of a turbine engine blade;    -   each of said moving means comprises an imprint representative of        one of the external faces of said reinforcement for the leading        edge or trailing edge of a turbine engine to be produced.

Other characteristics and advantages of the invention will more clearlyemerge from the description given below, for indicative and in no waylimiting purposes, with reference to the attached figures, among which:

FIG. 1 is a perspective view of the forming tooling according to theinvention illustrated in its open position;

FIG. 2 is a side view of the tooling according to the invention during aclosing phase;

FIG. 3 is a side view of the forming tooling according to the inventionin its closed position;

FIG. 4 is a side view of the forming tooling according to the inventionillustrating the tooling during an opening phase;

FIG. 5 is a side view of the tooling according to the inventionillustrating the forming tooling in its open position.

In all figures, common elements bear the same reference numbers, unlessotherwise indicated.

FIG. 1 is a perspective view of the forming tooling 100 according to theinvention illustrated in its open position.

The forming tooling 100 is conventionally formed by a lower part 110,representing the fixed part of tooling 100, and an upper part 120,representing the moving part of tooling 100.

The forming tooling 100 represented, by way of example, in all figuresis a tooling enabling a titanium reinforcement for the leading edge of aturbine engine blade to be made.

The tooling is intended to be assembled on a single action press (notrepresented), of the forging press type, comprising a single workingaxis, generally the vertical axis, illustrated in FIG. 1 by the Z axis.

According to other embodiments, the tooling may also be mounted on anytype of pressure forging machine comprising a single working axis.

In general, a forged workpiece is fabricated by placing a preform or ablank between two dies, an upper die and a lower die, each comprising anappropriate imprint (or cavity), and then by moving the two dies closertogether with a pressure sufficient to deform the preform until aworkpiece whose geometry corresponds to that of the imprints isobtained, the forging operation being carried out with the heatedtooling, i.e. a tooling at a temperature greater than 850° C. forproducing a titanium workpiece and advantageously at a temperature onthe order of 940° C. (plus or minus 10%).

The lower part 110 of the tooling comprises, in particular:

-   -   a lower support 111 capable of being connected to the single        action press (not represented);    -   a lower die 112 presenting an imprint 113 suitable for        fabricating a leading edge reinforcement;    -   two support plates 116 bordering both sides of the lower die        112, each of which comprises, in its upper part, a notch 117        capable of forming a reference for positioning the preform 10        before the tooling is closed.

In FIG. 2, illustrating a side view of the forming tooling according tothe invention illustrated in its open position, some elements, such asthe support plates 116, are not represented in order to enable thelayout of the lower die 112 to be seen more clearly.

The lower die 112 is formed by:

-   -   a first lower part 112 b connected to support 111, for example        by a screw assembly comprising at least two longitudinal grooves        119, at the level of its upper face distributed on both sides of        the longitudinal center line of the lower part 112 a,        illustrated by the X axis;    -   a second upper part 112 a presenting at the level of its lower        face positioning lugs 118 enabling the upper part 112 a to be        positioned in the grooves 119 of the lower part 112 b; each lug        118 having the complementary shape of the shape of the        longitudinal grooves 119 of the first lower part 112 a.

The second upper part 112 a is connected to the first part by connectionmeans 132 forming pins and traversing both the first lower part 112 a atthe level of the longitudinal grooves 119 and the positioning lugs 118of the upper part 112 b.

The lower die 112 comprises a punch 114, the upper part of which formsan imprint 113 in conformance with the inner geometry of the leadingedge of the turbine engine blade.

The lower part 112 b of the die 112 presents a flare, substantially inthe shape of an isosceles trapezoid, capable of receiving the base ofthe punch 114, also in a trapezoidal shape, and capable of centering thepunch 114 in die 112.

The base of the punch 114 is trapped between the lower part 112 a andthe upper part 112 b of the die 112, and more specifically in a space114 bordered on the one hand by the flare of the lower part 112 a and onthe other hand by two horizontal lugs 133 projecting inside the upperpart of tooling 110.

Thus, these two horizontal lugs 133 of the upper part 112 b perform astop function only allowing a certain vertical displacement (i.e., inthe Z axis represented in FIG. 1) of the base of punch 114 in thedefined space 115.

The clearance thus created advantageously enables a calibrateddisplacement between these different pieces of die 112, creating a punch114 floating in space 115 that is capable of facilitating the unmoldingof the workpiece made in tooling 100.

Other transversal and longitudinal displacements of punch 114 arerespectively blocked by the tapered shape of the lower part 112 areceiving the base of punch 114 as well as by the support plates 116bordering both sides of punch 114.

Support plates 116 are connected to the lower part 112 a of die 112 byconventional connection means used in this type of forging presstooling.

The upper part 120 of the tooling comprises, in particular:

-   -   an upper support 123 capable of being connected to the single        action press (not represented);    -   two upper dies 121 and 122, each of which presents an imprint,        respectively referenced 124 and 125, corresponding to the outer        geometry of one of the faces of the reinforcement for the        leading edge of a turbine engine blade to be produced.

The two upper dies 121 and 122 have the characteristic of generating acomplex movement different from the displacement imposed by the singleaction press.

FIG. 2 more specifically illustrates the respective movements of the twodies 121, 122, by arrows referenced 150, during closing of the press, inwhich the opening/closing displacement is symbolized by vertical arrows160.

In fact, the two upper dies 121, 122 perform a translational movement inthe Y axis, during displacement of the upper support 123 in the Z axis.The translational movement of upper dies 121, 122 during closing of thepress is allowed by the complementary shape of upper dies 121, 122 andthe lower die 112.

Face 131 of the lower die 112 that inwardly faces tooling 100 forms aslope on which upper dies 121, 122 slide during closing of the press, bygenerating a transverse displacement complementary to the verticaldisplacement in the Z axis.

The transverse movement of upper dies 121, 122 is relatively guided by aguide 134, for example a free cylindrical pin, enabling the two upperdies 121, 122 to be guided during closing and during opening of thepress.

Consequently, the two upper dies 121, 122 initiate the deformation andpossibly the twisting of preform 10, introduced in the tooling, duringthe closing of the tooling and from the start of the closing phase oftooling 100.

The upper dies 121 and 122 comprise a bearing surface 135 on their upperpart, on which the support 123 transmits the thrust of the press. Thisbearing surface is oriented substantially perpendicularly to thedirection of thrust of the upper dies 121, 122, illustrated by arrows150. The orientation of this bearing surface 135 limits the torquegenerated on upper dies 121, 122 and thus prevents the upper dies 121,122 from twisting when the press is closed.

FIG. 3 illustrates the forming tooling 100 described previously in theclosed position.

As the upper part 120 of tooling 100 rises, in the opening phase, asillustrated in FIGS. 4 and 5, two spacers 141 (only one is shown)integral with the upper support 123 enable, by virtue of their shape,the two upper dies 121, 122 to be moved away from the forged workpiece.

The spacers 141 present an outer beveled surface 136 forming a slope andproducing a bearing surface capable of sliding on upper dies 121, 122during opening of tooling 100. Therefore, during the upward movement ofupper tooling 120, the spacers 141 rise vertically, according to thearrow referenced 161, illustrated in FIG. 4, enter in contact with upperdies 121, 122 and then push in this manner upper dies 121, 122 in atransverse direction, perpendicular to the direction of opening oftooling 100. When the spacers 141 are in contact with the two upper dies121, 122, they have a surface 137 supported on the outer surface 136 ofspacers 141, such that the upward movement of spacers 141 moves, underthe effect of gravity, the upper dies 121, 122 apart by sliding both onthe surface 136 of spacer 141 and on the bearing face 131 of lower die112 in the direction illustrated by the arrow referenced 151. FIGS. 4and 5 respectively illustrate the tooling in the low position during theupward movement phase of the press and the tooling in the high positionduring the upward movement phase of the press.

In the high position, as illustrated in FIG. 5, the upper dies arepositioned supported on spacers 141 by means of horizontal stops 138 andslopes 137. Therefore, the device is operational for forming the nextworkpiece.

Thanks to the invention, the automatic spacing (as opposed to manualspacing by an operator) enables the tooling to be quickly prepared toform the next workpiece without operator intervention and withoutcooling of the tooling.

In order to facilitate unmolding of the workpiece produced, particularlycold produced, imprint 113 may be constituted of a plurality of movableor removable sections capable of being individually disassembled.

In order to facilitate unmolding, it is also possible to initiallyprepare the tooling 100 by depositing a protective layer on imprints113, 124, 125 so as to prevent the forged workpiece from adhering to thetooling 100. By way of example, this protective layer may be a layer ofaluminum oxide.

The invention was particularly described for making a metalreinforcement for a composite turbine engine blade; however, theinvention is also applicable for making a metal reinforcement for ametal turbine engine blade.

The invention was particularly described for making a metalreinforcement for a leading edge of a turbine engine blade; however, theinvention is also applicable for making a metal reinforcement of atrailing edge of a turbine engine blade.

Other advantages of the invention are, in particular, as follows:

-   -   reduced production costs;    -   reduced production time;    -   simplified manufacturing process;    -   reduced tooling costs;    -   reduced material costs.

1. A multi-form forming tooling capable of high temperature forming of ametal workpiece, said tooling comprising a fixed part and a moving partto be set in action by a one-way press, in a first direction, saidtooling varying between an open position and a closed position in whichthe moving part applies pressure to said fixed part, wherein said movingpart comprises moving dies constructed and arranged to initiatedeformation of said metal workpiece through a translational movement ofsaid dies in a second direction simultaneous with the translationalmovement of said dies in said first direction during said closure ofsaid tooling, said moving dies constructed and arranged to move awayfrom said metal workpiece through a reverse translational movement ofsaid moving dies, in said second direction, simultaneously with thetranslational movement of said moving dies, in said first direction,during said opening of said tooling.
 2. The multi-form forming toolingaccording to claim 1, wherein said tooling is an isothermal toolingcapable of forming at a temperature greater than 850° C.
 3. Themulti-form forming tooling according to claim 1 wherein said fixed partcomprises a die presenting two inclined walls capable of displacing saidmovable dies in said second direction during said closing of saidtooling.
 4. The multi-form forming tooling according to claim 3, whereineach of said movable dies comprises an inclined face parallel to one ofsaid inclined walls of said die of the fixed part.
 5. The multi-formforming tooling according to claim 1 wherein said movable part comprisesat least one spacer integral with the movements of said moving partcapable of moving said movable dies of said workpiece apart in saidsecond direction during said opening of said tooling.
 6. The multi-formforming tooling according to claim 1, wherein said fixed part comprisesmeans capable of forming a reference enabling said metal workpiece to bepositioned in the tooling.
 7. The multi-form forming tooling accordingto claim 1, wherein said tooling is capable of forming a metalreinforcement for the leading edge or trailing edge of a turbine engineblade.
 8. The multi-form forming tooling according to claim 7, whereineach of said movable dies comprises an imprint representative of one ofthe outer faces of said reinforcement for the leading edge or trailingedge of a turbine engine to be produced.
 9. The multi-form formingtooling according to claim 6, wherein said means capable of forming areference enabling said metal workpiece to be positioned in the toolingincludes one or more support plates.
 10. A multi-form forming toolingcapable of high temperature forming of a metal workpiece, said toolingcomprising a fixed part and a moving part to be set in action by aone-way press, in a first direction, said tooling varying between anopen position and a closed position in which the moving part appliespressure to said fixed part, wherein said moving part comprises movingmeans capable of initiating deformation of said metal workpiece througha translational movement of said means in a second directionsimultaneous with the translational movement of said means in said firstdirection during said closure of said tooling, said moving means beingcapable of moving away from said metal workpiece through a reversetranslational movement of said moving means, in said second direction,simultaneously with the translational movement of said moving means, insaid first direction, during said opening of said tooling.
 11. Themulti-form forming tooling according to claim 10, wherein said movingmeans include a plurality of moving dies.